100 check-ins occurring around 75a85a1c6ac59f2d.

Add the SQLITE_CONFIG_MMAP_LIMIT configuration option for overriding the
SQLITE_DEFAULT_MMAP_LIMIT compile-time setting. Enhance "PRAGMA mmap_limit"
so that without a specific database name, it sets the limit on all database
files and changes the default for any future databases that might be added
using ATTACH.
check-in: 78141d0a user: drh tags: experimental-mmap

In order to optimize out the ORDER BY clause,
outer loops must generate values for ORDER BY terms that are unique or else
the inner loops must generate no more than a single row.
Fix for ticket [a179fe7465].
check-in: 2936f746 user: drh tags: trunk

A fix and test-case for the ORDER BY problem identified by ticket [a179fe7465].
This change causes sorting to occur in some cases where it is not strictly
necessary. Further work is needed to avoid those extra sorts.
check-in: 488089e6 user: drh tags: orderby-fix

Memory-mapped I/O is now on by default. The "PRAGMA mmap_limit(N)" can be
used to issue a hint to the VFS to limit mmap space to N bytes. The VFS
is free to ignore that hint if desired. However, if "PRAGMA mmap_limit(0)"
is used, xFetch is never called.
check-in: 1b37c4ef user: drh tags: experimental-mmap

Remove unnecessary code to round the size of a memory mapping to 4KB from os_unix.c. Rename SQLITE_IOERR_MREMAP to SQLITE_IOERR_MMAP. Fix other small issues in os_unix.c.
check-in: dce35c01 user: dan tags: experimental-mmap

Add assert statements to os_unix.c to ensure that any mapped region of the database file is not being read or written using the xRead() or xWrite() methods.
check-in: 765615f9 user: dan tags: experimental-mmap

Fix text-to-numeric type casting so that it works correctly on UTF16
strings that contain characters where the LSB is numeric but the MSB
is non-zero. Ticket [689137afb6da41]check-in: 5b22053f user: drh tags: trunk

Adjust the MSVC makefile so that it correctly handles the sessions
extension being included in the amalgamation. Import the test case
changes that appeared in 3.7.16 final.
check-in: 9bac09a9 user: drh tags: sessions

Fix the ORDER BY with IN constraint logic so that it works with all
combinations of DESC on the ORDER BY clause, on the RHS of the IN operator,
and in the index used by ORDER BY and IN.
Fix for ticket [4dd95f6943fbd18].
check-in: 839aa91f user: drh tags: trunk

Add a single new test case to the ORDER BY with IN logic verify that if the
RHS of the IN is a descending index that it still works. Add testcase()
macros to the ORDER BY with IN logic to help verify that corner cases are
tested.
Closed-Leaf
check-in: 7e7356f1 user: drh tags: desc-orderby-fix-1